Bougainville

Introduction to the Invasion of Bougainville Island

After New Georgia, the next major operation was an invasion of the island of Bougainville, which was approached by landings at Mono and Stirling in the Treasury Islands on October 25-27, 1943. A Marine division landed on the west coast of Bougainville at Empress Augusta Bay on November 1, 1943. The Marines were followed within the month by an Army division and replaced in the next month by another Army division.

It was late November before the beachhead at Empress Augusta Bay was secure. This beachhead was all that was needed, and no attempt was made to capture the entire island. Allied planes neutralized enemy airfields in the northern part of the island, and the Allied command made use of its naval and air superiority to contain the Japanese garrison on
Bougainville and cut its supply line to Rabaul by occupying the Green Islands (February 14, 1944).

Despite these measures, the Japanese maintained pressure against the beachhead, mounting an especially heavy but unsuccessful counterattack as late as March 1944. Success at Bougainville isolated all Japanese forces left in the Solomons. The Japanese sustained comparatively heavy air and naval losses during the campaign, which further crippled the Japanese Combined Fleet and had a vital effect on the balance of naval power in the Central
Pacific.